include/Field.h

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by www.databasecache.com                           *
   3  *   Contact: praba_tuty@databasecache.com                                 *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15   ***************************************************************************/
  16 #ifndef FIELD_H
  17 #define FIELD_H
  18 #include<os.h>
  19 #include<DataType.h>
  20 #include<ErrorType.h>
  21
  22 //used by FieldNameList
  23 class FieldNameNode
  24 {
  25     public:
  26     char  fldName[IDENTIFIER_LENGTH];
  27     FieldNameNode *next;
  28 };
  29
  30
  31 class FieldDef
  32 {
  33     public:
  34     FieldDef()
  35     {
  36         init();
  37     }
  38     void init() {
  39         type_ = typeUnknown;
  40         length_ = 0;
  41         bindVal_ = NULL;
  42         isDefault_ = false;
  43         isNull_ = false;
  44         isPrimary_ = false;
  45         isUnique_ = false;
  46         strcpy(fldName_, "");
  47     }
  48     char fldName_[IDENTIFIER_LENGTH];
  49     DataType type_;
  50     size_t length_;
  51     //currently default value is supported for string and binary
  52     //less than length 32 bytes
  53     char defaultValueBuf_[DEFAULT_VALUE_BUF_LENGTH];
  54
  55     //used only in case of binding fields
  56     void *bindVal_;
  57
  58     bool isNull_;
  59     bool isPrimary_;
  60     bool isDefault_;
  61     bool isUnique_;
  62     //TODO::width and scale
  63 };
  64
  65 class FieldNode
  66 {
  67     public:
  68     FieldDef fldDef;
  69     FieldNode *next;
  70 };
  71
  72
  73 class FieldIterator
  74 {
  75     public:
  76     FieldNode *iter;
  77     FieldIterator(FieldNode *ptr) { iter = ptr; }
  78     bool hasElement()
  79     {
  80         if (iter == NULL) return false; else return true;
  81     }
  82     FieldDef nextElement()
  83     {
  84         if (iter == NULL) { FieldDef dummyDef; return dummyDef;}
  85         FieldNode *node = iter;
  86         iter = iter ->next;
  87         return node->fldDef;
  88     }
  89 };
  90
  91 class FieldInfo;
  92
  93 //Internal class used to implement the field list information
  94 //to create the table
  95 class FieldList
  96 {
  97     public:
  98     FieldNode *head;
  99     FieldList(){ head = NULL;}
 100
 101     //TODO::pass by reference instead of value
 102     DbRetVal append(FieldDef fDef);
 103
 104     DbRetVal remove(const char* fldName);
 105
 106     DbRetVal removeAll();
 107
 108     DbRetVal updateBindVal(const char *fldName, void *val);
 109     void * getBindField(const char *fldName);
 110     int getFieldOffset(const char *fldName);
 111     int getFieldOffset(int fldpos);
 112
 113     //Returns position of field in the list:count starting from 1
 114     int getFieldPosition(const char *fldName);
 115
 116     DataType getFieldType(const char *fldName);
 117
 118     size_t getFieldLength(const char *fldName);
 119
 120     DbRetVal getFieldInfo(const char *fldName, FieldInfo *&info);
 121
 122     int getTupleSize();
 123
 124     FieldIterator getIterator()
 125     {
 126         FieldIterator iter(head);
 127         return iter;
 128     }
 129 };
 130 #endif